According to the levels of driving automation that are formulated by SAE International, a higher level of driving automation requires higher robustness and higher reliability for an active control system of an autonomous vehicle.
Limited by the time required for processing images captured by a camera of a lane tracking system, an update frequency for lane detection information is low (e.g., 10-20 Hz), and the lane detection information is hardly truly “real-time” from the perspective of vehicle motion control. For example, the lane detection information, such as lane line/marking information, is usually 100 ms to 200 ms old when provided to a vehicle control system. If a frequency of the vehicle control system controlling operation of the vehicle is limited by, for example, the lower update frequency of the lane detection information, the resolution and the precision of control instructions issued by the vehicle control system may be reduced, and the lane tracking performance may be adversely affected, which is especially evident in road sections with high curvature or when the vehicle is traveling with a larger lateral speed.
In addition, when lane lines/markings have deteriorated, are unclear or even absent, or present abnormal color contrast due to variations in light conditions, conventional lane tracking methods may not provide correct lane line information as normal.